Influence of the processing parameters and composition on the thermal stability of PLA/nanoclay bio‐nanocomposites

Poly(lactic acid) (PLA) is one the most promising bio‐based and biodegradable polymer. However, its low thermal stability limits the range of applications and complicates its transformation via the most industrial common processes. The novelty of this work is studying the thermal stability of PLA and PLA/clay nanocomposites during use, as a function of the composition and using a wide range of extrusion and injection moulding processing parameters. To improve the thermal stability of the PLA, laminar silicates containing different organomodifications have been added (Cloisite 20A and Cloisite 30B). The results show that the processing conditions and composition define the morphology of the bio‐nanocomposites, which plays key role in defining final thermal properties of the material. In general, clays improve the thermal stability of the processed material, increasing the degradation temperature and decreasing the degradation rate under a wide range of processing conditions. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40747.     

The factor structure of situational and dispositional versions of the Smith Irrational Beliefs Inventory in a Spanish student population.

This study attempted to identify and replicate the factor structure of English and Spanish versions of the Smith Irrational Beliefs Inventory (SIBI). Factor analyses of irrational beliefs have yielded conflicting results. In contrast to the results of studies on clinical populations, studies on college students have mostly resulted in unifactorial solutions. Factor analyses of situational and dispositional Spanish versions of the SIBI on 960 Spanish college students resulted in 7 factors: Negativity, Distorted Egocentrism, Perfectionism, Catastrophizing-Task Exaggeration, Minimizing-Avoiding, Needless Other- Blaming, and Distorted Isolation. The results suggest that the SIBI displays a consistent factor structure across cultures and situational/dispositional formats. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lithium Phosphonate Functionalized Polymer Coating for High-Energy Li[Ni0.8Co0.1Mn0.1]O2 with Superior Performance at Ambient and Elevated Temperatures

High-energy Ni-rich lithium transition metal oxides such as Li[Ni_0.8Co_0.1Mn_0.1]O₂ (NCM₈₁₁) are appealing positive electrode materials for next-generation lithium batteries. However, the high sensitivity toward moist air during storage and the high reactivity with common organic electrolytes, especially at elevated temperatures, are hindering their commercial use. Herein, an effective strategy is reported to overcome these issues by coating the NCM₈₁₁ particles with a lithium phosphonate functionalized poly(aryl ether sulfone). The application of this coating allows for a substantial reduction of lithium-based surface impurities (e.g., LiOH, Li₂CO₃) and, generally, the suppression of detrimental side reactions upon both storage and cycling. As a result, the coated NCM₈₁₁-based cathodes reveal superior Coulombic efficiency and cycling stability at ambient and, particularly, at elevated temperatures up to 60 ° C (a temperature at which the non-coated NCM₈₁₁ electrodes rapidly fail) owing to the formation of a stable cathode electrolyte interphase with enhanced Li⁺ transport kinetics and the well-retained layered crystal structure. These results render the herein presented coating strategy generally applicable for high-performance lithium battery cathodes.     

Drying of Biomass in a Conical Spouted Bed with Different Types of Internal Devices

The drying of sawdust was studied in a conical spouted bed pilot plant in order to adapt this feed for the pyrolysis process. Air at different temperatures was used and the effect of sawdust particle size and operating gas velocity was studied. Batch operation was performed with no internal device and with nonporous and open-sided draft tubes in order to ascertain the optimum configuration of the contactor. Although the nonporous draft tube required the lowest minimum spouting velocity, its performance was poor due to deficient gas–solid contact. Configurations with open-sided draft tubes and with no internal devices had higher efficiencies because of their better contacts. An increase in air temperature resulted in a reduction in drying time but the operating conditions need to be fine-tuned to ensure proper energy efficiency.     

How Can We Improve Vaccination Response in Old People? Part I: Targeting Immunosenescence of Innate Immunity Cells

Vaccination, being able to prevent millions of cases of infectious diseases around the world every year, is the most effective medical intervention ever introduced. However, immunosenescence makes vaccines less effective in providing protection to older people. Although most studies explain that this is mainly due to the immunosenescence of T and B cells, the immunosenescence of innate immunity can also be a significant contributing factor. Alterations in function, number, subset, and distribution of blood neutrophils, monocytes, and natural killer and dendritic cells are detected in aging, thus potentially reducing the efficacy of vaccines in older individuals. In this paper, we focus on the immunosenescence of the innate blood immune cells. We discuss possible strategies to counteract the immunosenescence of innate immunity in order to improve the response to vaccination. In particular, we focus on advances in understanding the role and the development of new adjuvants, such as TLR agonists, considered a promising strategy to increase vaccination efficiency in older individuals.     

Teaching model-driven engineering from a relational database perspective

We reinterpret MDE from the viewpoint of relational databases to provide an alternative way to understand, demonstrate, and teach MDE using concepts and technologies that should be familiar to undergraduates. We use (1) relational database schemas to express metamodels, (2) relational databases to express models, (3) Prolog to express constraints and M2M transformations, (4) Java tools to implement M2T and T2M transformations, and (5) Java to execute transformations. Application case studies and a user study illuminate the viability and benefits of our approach.     

Surface functionalization of polyolefin films via the ultraviolet‐induced photografting of acrylic acid: Topographical characterization and ability for binding antifungal agents

The photoinduced graft copolymerization of acrylic acid with ultraviolet radiation onto films of poly(vinyl chloride), polypropylene, and polyethylene was studied. Benzophenone was used as the initiator for most of the experiments performed. The percentage of grafting was determined by gravimetric measurements, and the characterization of the grafted films was carried out by chemical analysis (Fourier transform infrared spectroscopy, volumetric titration, and dye adsorption). In all samples, the grafted yield increased with the ultraviolet exposure time. High levels of grafting were obtained at room temperature. In addition, optical and atomic force microscopy allowed the topography of the modified films to be studied as a function of the reaction time. The pendant functional groups that were grafted were then used to bind antifungal agents, such as natamycin and crystal violet, and the antifungal properties of the films were demonstrated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:2254–2263, 2006     

Relationship between the network morphology and properties of commercial vinyl ester resins

Two commercial vinyl ester resins, Derakane 411‐350 (resin D) and Derakane 411‐350 Momentum (resin M), were characterized. Despite the large quantity of publications in the literature about vinyl ester resins, few experimental results have been reported for resin M. The effect of the styrene content on the mechanical properties and morphological structure was studied. An increase in the styrene content produced a network with a low storage modulus in the rubber state and a glass‐transition temperature. The apparent average molecular weight between crosslink points and glass‐transition temperature were slightly higher for resin D than for resin M. The Fourier transform infrared spectra and molecular weight distributions were similar. However, resin M was tougher than resin D, and this may have been due to the closer structure in the fully cured state. Atomic force microscopy was performed for each cured resin and confirmed the difference in the nanostructures. The main reason for the differences in the developed structures was the use of an accelerator, which influenced the final morphology. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3895–3903, 2006